The Republican incumbent had protested the result, but his opponent’s vote lead grew

RALEIGH, N.C.—Republican Gov. Pat McCrory of North Carolina conceded his bid for re-election to Democrat Roy Cooper on Monday, ending a monthlong skirmish over the incumbent’s unsubstantiated claims of voting irregularity.

The governor’s race was extremely close, but the tally of absentee and provisional votes drove Mr. Cooper’s lead to more than 10,000 votes, up from about 5,000 votes out of 4.7 million cast in unofficial results on Election Day. Mr. McCrory’s team had filed protests in dozens of counties, claiming that...